The background description provided herein is for generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art or suggestions of the prior art, by inclusion in this section.
The conventional long term evolution (LTE) system utilizes spectrum that is exclusively assigned to a corresponding LTE service provider (or operator), referred to as LTE in Licensed Spectrum, or simply LTE. Due to an upsurge in demand for wireless broadband data, various approaches are being considered for increasing data throughput of the LTE system. One approach under consideration is to use the LTE system to transmit data through unlicensed spectrum as well as licensed spectrum. The LTE system operating in unlicensed spectrum is often referred to as LTE in Unlicensed Spectrum or LTE-U. Unlicensed spectrum is typically shared with other radio access technologies (RATs) such as IEEE 802.11x (WiFi) or the same RAT deployed by different operators. Therefore, one of the design issues of LTE-U is how to efficiently share the spectrum, also referred to as wireless communications medium, with other RATs and/or operators.